Generally, the bottom of Chagan Lake is 126 meters above sea level, with a maximum water surface of 307 square kilometers and a water depth of 4 meters. It is the largest natural lake in Jilin Province, with a perimeter of 104.5 km, a maximum storage capacity of 4150,000 cubic meters, a length of 38 km from east to west and a width of 14 km from north to south. 1960, Taoer River flooded into Chagan Lake, which reached the west of Miao Xin and is now a first-class highway. After 1962, Hangali, Xinglong, Shengli and other reservoirs were built in the upper reaches of Huolin River to store water layer by layer, so that the amount of water entering the lake decreased or even stopped, the water surface decreased and the PH value increased. By 1972, the lake surface had shrunk to more than 50 square kilometers, and the pH value had increased from 8.5 to 12.8. In 1974, it dried up, and the alkaline soil was flying at the bottom of the lake, causing alkali damage to more than 70,000 mu of cultivated land and 80,000 mu of grassland around it.

Starting from 1976 (one said 1980), the water diversion project from Xibotun to Chagan Lake on the left bank of Songhua River was excavated for 54 kilometers. The design water conveyance capacity of the diversion canal is 85 cubic meters per second, and it is sent to Chagan Lake through Miao Xin bubble connecting Xindian bubble, so that the three bubbles are connected into a whole, and the water surface of Chagan Lake is expanded year by year. The three lakes have a total water surface of 375 square kilometers, a total storage capacity of 598 million cubic meters and a total water area of 403 square kilometers. 1985 has stored 450 million cubic meters of water, and by the end of 1985, the water level has basically recovered to 130 meters. Through the "water diversion project", the pH value of Songhua River water was 6.97, which was diluted to 8.8 at 1985 after entering the lake, and the water quality of the lake was improved from grade 5 to grade 3. The fish yield is19810.5 million tons,10.5 million tons. Degraded reed recovered from 198 1

1983, Xinli Oil Production Plant of Jilin Oilfield pumped oil at the bottom of Chagan Lake, and built a 9.8-kilometer dam from Aobaoshan (that is, Guojiazitun after Difangzitun) to Shijiazitun, cutting off an area of 200,000 mu of Chagan Lake. 1986, the floods of Huolin River and Taoer River entered Chagan Lake, and the highest water level of Chagan Lake was 13 1.23 m, and the floods lasted for a winter and spring in Chagan Lake. 1998, the Huolin River and Nenjiang River suffered another catastrophic flood, and the water level of Chagan Lake once rose to 132.02 meters, the highest level since written records in history. On June 5438+ 10, 2003, Chagan Lake Tourism Economic Development Zone built a new dam with a length of 9.3 kilometers in the southeast oil field dam of Chagan Lake, which separated the water in Chagan Lake and established a 10,000-mu fish pond breeding base. So far, the surface of Chagan Lake has decreased by 10.38 square kilometers. According to the interpretation and analysis of TM image (American satellite TV) data on September 10, 2003, the lake area of Chagan Lake is 370 square kilometers (including Xindianpao). 1999 ~ 2007, the water level of Chagan Lake remained basically stable, supplemented by the drainage from Guo Qian irrigation area and the surface runoff in dry season. The water level was 130 ~ 130.25m, and there was no water supply in winter. Due to evaporation and infiltration, the water level was130 ~/.

According to the entries in China River and Lake Grand Ceremony, Chagan Lake is 37 kilometers long, 0/7 kilometers wide and 228.5 square kilometers in water surface area ... The coastline of the lake is tortuous, with a length of 0/28 km and a storage capacity of 589 million cubic meters, with an average water depth of 2.5 meters and the deepest point of 6 meters. When the water level of Chagan Lake is 130m, it is integrated with Xindian Bubble and Maying Bubble, and its sister bubbles are Miao Xin Bubble and Curry Bubble. The surface area of Xinmiaopao is 3 1 km2, and the water level is130.5m.. Located on the southeast bank of Chagan Lake, with a distance of 1.25 km, it is connected by a diversion canal, and the water level between the lake and bubbles is controlled by a sluice at the end of the canal. When the water level in the reservoir is 129 meters, the water surface area is 14 square kilometers. It is connected by Chagan Lake sluice and overflow weir, with a distance of 7 kilometers. Chagan Lake is connected end to end by two sisters, with different altitudes and a total area of 420 square kilometers.

The main features of Chagan Lake landform are low-level microwave fluctuation, high in the southeast, slightly higher in the southwest and low in the middle and northeast. The terrain around Dongchuantou, Xichuantou and Qingshantou of Chagan Lake is relatively high, ranging from140m to160m. Chagan Lake is low-lying, and there are secondary valley terraces left by the lake. The water levels of several great lakes are different, and there are also some sand dunes with a relative height of less than 5 meters. According to the genesis and morphological characteristics, the landform in this area can be divided into alluvial lacustrine plain and valley alluvial plain. The alluvial lacustrine plain is distributed in the low-lying area of Chagan Lake, and the valley alluvial plain is distributed in Huolin River valley and Nenjiang ancient river channel.

Chagan Lake is a lake formed by rivers, which was once a part of the main channel of Nenjiang River in history. Due to crustal movement, climate change, river swing, siltation and other reasons, Nenjiang River diverted eastward to the east of Daan platform, leaving Daan ancient channel. On the other hand, the incoming water of the tributary Huolin River gradually decreases, the river course gradually silts up, and the outlet is blocked, forming a blind tail river. In addition, the terrain here is flat and the drainage is not smooth. Therefore, the largest freshwater lake in Jilin Province, called "800 Sea", was formed in the west of Jilin Province. The east and north are surrounded by mountains with a height difference of 5-20 meters. There are farmland, grassland and forest around the lake, which is located in the water network area where Nenjiang River and Huolin River meet.